 And yet it is hard to believe that anythingin nature could stand revealed as solid matter.The lightning of heaven goes through the walls of houses,like shouts and speech; iron glows white in fire;red-hot rocks are shattered by savage steam;hard gold is softened and melted down by heat;chilly brass, defeated by heat, turns liquid;heat seeps through silver, so does piercing cold;by custom raising the cup, we feel them bothas water is poured in, drop by drop, above.Book I, lines 487-496.